Here is the very first photo ever taken of the black hole of the Milky Way!

Here is the very first photo ever taken of the black hole of the Milky Way!

For the first time, researchers have succeeded in producing a direct image of Sagittarius A*, the supermassive black hole that structures the Milky Way.

[Article mis à jour en temps réel]

That’s it ! After two weeks of unbearable suspense, researchers from the European Southern Observatory have finally unveiled the work “revolutionaries” on the Milky Way that they teased two weeks ago. And the predictions of the observers turned out to be correct: for the very first time, they managed to capture a direct image of Sagittarius A*, the huge supermassive black hole that structures our entire galaxy!

It is a simply phenomenal first in many respects, and which fully deserves the qualifier of “revolutionary” used by researchers. Because even if he was commonly accepted that it is a black hole, this information had never been confirmed with absolute certainty.

The most conclusive results were brought by the exceptional work of Reinhard Genzel and Andrea Ghez; they succeeded in proving that Sgr A* is a extremely compact supermassive objectfor which a black hole represents the only plausible explanation under current models. A deduction that earned them a Nobel prize. All that remained was to make a direct observation of it, and this is what the researchers succeeded in doing, not without difficulty.

For decades we knew that an extremely compact object was located at the center of our galaxy”, explain the researchers. “All scans indicated it was a black hole, and for the first time ever, we were able to confirm it”.

An infinitely complicated observation to make

Remember that black holes are by definition very unphotogenic objects. They have the annoying habit of absorbing all electromagnetic radiation, including light. It is therefore physically impossible to observe the black hole itself; on the images, we can only make out an empty zone at this location.

Astronomers must content themselves with looking for the horizon, a limit materialized by a disc of superheated gas which accumulates on the periphery of the singularity while emitting very intense radio radiation; this is the orange halo in the image. A veritable cosmic beacon which one might intuitively think would be easy to photograph, knowing that it is also 4 million times heavier than the Sun… but it is in fact quite the opposite.

© ESO / EHT

Indeed, this cosmic giant is partially masked by an immense cloud of dust and gas; an obstacle that further complicated an already immensely daunting task for astronomers’ telescopes.

To achieve this, they had to push the Event Horizon Telescope to its limits by bringing together lots of telescopes around the world for years. They passed the baton over the rotation of the Earth to constitute together a gigantic instrument of observation on the scale of the planet.

Despite this formidable weapon, the researchers also had to redouble their patience and ingenuity. They had to multiply the calibration, modeling and questioning phases. They also had to develop brand new algorithmic tools in order to grind more than 6 TB of encrypted data using several super-powerful supercomputers.

A daunting technological arsenal, but which was not too much to achieve the “most complex scientific image to date”, according to the researchers. And after years of effort and sleepless nights, doubt is no longer allowed: Sagittarius A* is indeed a supermassive black hole, and researchers now have its photo ID.

Einstein was right (again)

The other exceptional aspect of this work is its consistency. Indeed, all the observations corresponded precisely to the predictions made by the Nobel-winning works of 2020. They also perfectly match the theory of general relativity formulated by Einstein, down to the smallest detail. This work has therefore contributed to proving, once again, the exceptional solidity of this more than a century-old theory.

And the most interesting thing is that this is just the beginning. From now on, the researchers intend to draw the portrait with even more details. And it’s not just about visual curiosity. By getting as close as possible to the black hole, the researchers hope to highlight some of the breaking points of general relativity that has remained indestructible for decades.

And this is not a destructive fad, but fundamental work. Because it is by exploring these gray areas that they will perhaps one day arrive at the famous Theory of Everything which will reconcile particle physics with general relativity. There is therefore no doubt that despite this astonishing work, the researchers at the helm of the EHT will still gratify us with superb discoveries in the future.

Leave a Comment

Your email address will not be published.